NOTE: At least 10 the following questions will be in EXAM 2
Chapter 7: How to handle exceptions and validate data
Private Sub btnCalculate_Click(ByVal sender as System.Object, _
ByVal e As System.EventArgs) Handles btnCalculate.Click
Dim weightInPounds As Decimal = 0d
Try
weightInPounds = Convert.ToDecimal(txtPounds.Text)
If weightInPounds > 0 Then
Dim weightInKilos As Decimal = weightInPounds / 2.2d
lblKilos.Text = weightInKilos.ToString("f2")
Else
MessageBox.Show("Weight must be greater than 0.", "Entry error")
txtPounds.Select()
Catch ex As FormatException
MessageBox.Show("Weight must be numeric.", "Entry error")
txtPounds.Select()
End Try
End Sub
1.(Refer to code example 7-1.) What type of data validation does this program do?
a. / range checking onlyb. / valid data type checking only
c. / range checking and valid data type checking
d. / it doesn’t do any data validation
ANS:C
2.(Refer to code example 7-1.) If the user clicks the Calculate button without entering data in the text box, what does the code do?
a. / It calculates the weight in kilograms.b. / It causes a runtime error.
c. / It displays a dialog box with the message “Weight must be greater than 0.”
d. / It displays a dialog box with the message “Weight must be numeric.”
ANS:D
3.What statement causes a new exception to occur?
a. / Finally / c. / Throwb. / Catch / d. / Try...Catch
ANS:C
4.You typically do not throw an exception
a. / when invalid data is detectedb. / to test an exception handler
c. / when the processing that’s done by a procedure can’t be completed
d. / after catching an exception and performing some processing
ANS:A
5.In Visual Basic, exceptions are
a. / objects / c. / in the Exception namespaceb. / classes
ANS:A
6.The code within a Catch block is executed when
a. / the code in the Try block doesn’t compileb. / the code in the Try block throws an exception
c. / the Try block finishes executing
d. / a runtime error occurs
ANS:B
Chapter 8: How to work with arrays and collections
1.When you declare and initialize the values in an array, you are actually creating an instance of what class?
a. / String / c. / ArrayListb. / SortedList / d. / Array
ANS:D
2.To refer to the ninth element in a one-dimensional array named sales, you code
a. / sales(8) / c. / sales(10)b. / sales(9) / d. / sales.Item(9)
ANS:A
3.Which of the following statements declares a valid rectangular array?
a. / Dim ra As String / c. / Dim ra()() As Stringb. / Dim ra(4,4) As String / d. / Dim ra()() As String(4)(4)
ANS:B
4.Which of the following statements determines the number of elements in a one-dimensional array named customers?
a. / Dim size As Integer = customers.UpperBoundb. / Dim size As Integer = customers.Length
c. / Dim size As Integer = customers.Size()
d. / Dim size As Integer = Arrays.Size(customers)
ANS:B
Chapter 9: How to work with dates and strings
1.In Visual Basic, dates and times are actually stored as the number of
a. / milliseconds that have elapsed since January 1, 0001b. / seconds that have elapsed since January 1, 0001
c. / minutes that have elapsed since January 1, 0001
d. / ticks that have elapsed since January 1, 0001
ANS:D
2.Which of the following statements does not create a DateTime object whose date is set to March 28, 2007 (assume the computer’s regional settings are configured for the United States)?
a. / Dim date As Date = "03/28/2007"b. / Dim date as DateTime = DateTime.Parse("03/28/2007")
c. / Dim date as Date = #03/28/2007#
d. / Dim date as DateTime = CDate(txtDate.Text)
ANS:A
3.Which property of the DateTime structure returns the current date with the time set to 12:00:00 AM?
a. / Todayb. / CurrentDate
c. / Now
d. / Date
ANS:A
4.If a variable named date contains a valid DateTime value, which of the following statements checks if the date falls in a leap year?
a. / Dim isLeap As Boolean = date.IsLeapYearb. / Dim isLeap As Boolean = date.IsLeapYear()
c. / Dim isLeap As Boolean = DateTime.IsLeapYear(date)
d. / Dim isLeap As Boolean = DateTime.IsLeapYear(date.Year)
ANS:D
5.Which statement determines the due date for an invoice that is due 45 days after the invoice date?
a. / Dim dueDate As DateTime = invoiceDate.Add(45)b. / Dim dueDate As DateTime = invoiceDate.AddDays(45)
c. / Dim dueDate As DateTime = invoiceDate.Add(new TimeSpan(45))
d. / Dim dueDate As DateTime = invoiceDate.Add(DateTime.DAYS, 45)
ANS:B
6.What is the value of startDate after the following statements are executed?
Dim startDate As New DateTime(2004, 3, 1)
startDate = startDate.AddMonths(3)
a. / March 1, 2004 / c. / January 3, 2004b. / June 1, 2004 / d. / March 3, 2004
ANS:B
Chapter 10: More skills for working with Windows forms and controls
1.What control do you use to create a group of radio buttons?
a. / group boxb. / button set
c. / button group
d. / border
ANS:A
2.How do you retrieve the selected item in a list box?
a. / With the SelectedItem property / c. / With the GetSelection methodb. / With the Selection property / d. / With the GetSelectedItem method
ANS:A
3.What event is raised when the user selects an item from the drop-down list of a combo box?
a. / SelectedIndex / c. / TextChangedb. / SelectedIndexChanged / d. / SelectedItem
ANS:B
4.What does the following code do?
For i As Integer = 1 To cboNumbers.Items.Count Step 2
cboNumbers.Items(i) = "XXX"
Next
a. / It changes the first item in the combo box to “XXX”.b. / It changes every item in the combo box to “XXX”.
c. / It changes every second item in the combo box to “XXX”.
d. / It doesn’t change any items in the combo box.
ANS:C
Chapter 11: How to create and use classes
1.In a three-layer application, the three layers are
a. / the business layer, the middle layer, and the database layerb. / the presentation layer, the middle layer, and the database layer
c. / the presentation layer, the access layer, and the database layer
d. / the presentation layer, the middle layer, and the dataset layer
ANS:B
2.When you design and develop business classes for an application, your goal is to
a. / allow development to be spread among members of a development teamb. / separate the business rules from the presentation and database logic
c. / make the application easier to develop and maintain
d. / all of the above
ANS:D
3.A class defines the properties and methods of
a. / a structure / c. / an objectb. / a value / d. / a member
ANS:C
4.The process of creating an object from a class is known as
a. / instantiation / c. / inheritanceb. / encapsulation / d. / modeling
ANS:A
5.What feature are you taking advantage of when you call the ToDecimal method of the Convert class without knowing how it’s coded?
a. / instantiation / c. / inheritanceb. / encapsulation / d. / modeling
ANS:B
Chapter 12: How to debug an application
1.When doesn’t Visual Studio enter break mode?
a. / When your application handles an exception that’s thrownb. / When the application reaches a breakpoint that has been set
c. / When you start the execution of an application by stepping through it
d. / When you select the Break All command from the Debug menu
ANS:A
2.One benefit of the new Edit and Continue feature is that it lets you
a. / find more than one bug in a single test runb. / find and fix more than one bug in a single test run
c. / find more than one bug in a test run without exiting from break mode
d. / find and fix more than one bug in a single test run without exiting from break mode
ANS:B
3.You can use the Step Out command to
a. / execute all statements in the rest of the application without interruptionb. / execute all statements in the rest of the current procedure without interruption
c. / execute all statements in the next procedure without interruption
d. / execute all statements up to the next breakpoint
ANS:B
4.What command steps through a program one statement at a time?
a. / Step Next / c. / Step Intob. / Step Over / d. / Step Out
ANS:C